This Bone Marrow and Stem Cell Transplant Program (BMSCTP) of the University of Pennsylvania Abramson Cancer Center (ACC) is among the largest and oldest in the nation. This active program sees patients of all ages, sexes and ethnic origins and conducts all forms of stem cell transplantation including autologous, allogeneic, non-myeloablative and cord blood, matched and mismatched, related and unrelated for a myriad of diseases. Dr. Edward Stadtmauer has been the PI of this BMT CTN Core Clinical Center and is also the Co-leader of the ACC Hematologic Malignancies Program and so access to patients for BMT CTN clinical trials is straightforward and this has been reflected in the impressive accrual from our center. Dr David Porter works very closely with Dr Stadtmauer and has been the Director of Allogeneic Bone Marrow Transplant and Immunotherapy for 14 years. 210 patients have been accrued from Penn to BMT CTN; the 3rd largest accrual of any single center. Penn investigators have demonstrated intellectual leadership in the Network; membership on 6 protocol teams (study chairs for 2) and chair of 3 committees. Penn investigators were key to the highly successful myeloma series of clinical trials. ACC led accrual in all 3 trials with protocol team leadership in all. Penn's BMSCTP remains consistently very active with 205 stem cell transplants conducted in 2009; 125 autologous, 80 allogeneic. The BMSCTP is supported by numerous ACC world- class research resources: Our research proposal, A PHASE III TRIAL OF TACROLIMUS/MTX WITH OR WITHOUT MARAVIROC (A CCR5 INHIBITOR) AS GVHD PROPHYLAXIS AFTER REDUCED INTENSITY ALLOGENEIC STEM CELL TRANSPLANTATION was chosen among many alternatives from Penn to demonstrate an area of our expertise, based on our own pilot study work, fill a major clinical need, namely the improvement of outcome for allogeneic HSCT by reducing GVHD, and can be completed in a timely fashion. These attributes of strong clinical research, patient care, thought leaders in the field and a documented enthusiasm and success in BMT CTN trials uniquely position our Center to promote the efficient comparison of novel treatment methods and strategies to benefit blood or marrow transplantation.